Merge pull request #665 to make adsorptionPt111 more flexible with lone pairs px.

The nodes in the adsorption correction file adsorptionPt111.py were rather restrictive. 
In most nodes it was specified that the generalR cannot have lone pairs p0.
This wasn't noticed as a problem because the R was mostly C in the training data.
However, this is not correct. In most cases, the R can also be replaced with O or N.

This PR makes the nodes more permissive, by changing the p0 to px whenever it is reasonable.

Nodes containing nitrogen were not fixed because Kirk is doing a complete overhaul of the nitrogen adsorption corrections.

Author: rwest